Physical Properties of Chestnut Honey-Pollen Powders Obtained by Different Drying Methods

Abstract

Honey and bee pollen of chestnut botanical origin are special among beekeeping products due to their rich bioactive components. Although these natural products can be directly consumed, they can be converted into different products to increase their consumption. Honey powder is a product that has been studied in recent years, and obtained by drying honey with various carrier substances such as gum arabic, starch, and maltodextrin. Moreover, the use of bee pollen as a carrier material has positive effects on the potential benefits of honey powders.

Herein, it was aimed to research the effect of spray and vacuum drying on bulk density, flowability, solubility, hygroscopicity, wettability, particle microstructure, and color properties of chestnut honey (Castanea sativa pollen: 93.28%) and bee pollen (Castanea sativa pollen: 82.75%) powder. Chestnut bee pollen, gum arabic, and water (1:1:10 w/w/v) were mixed at 400 rpm for 10 min and that mixture was added to chestnut honey and mixed at the same conditions. The prepared mixture was dried with spray (140°C, 14 mL/min flow rate, and 82% aspiration) and vacuum (45-60°C,  200 mbar) drying systems.

Carr index values as flowability indicator of spray and vacuum-dried samples were 42.02% and 33.70%, respectively. The flowability of honey powders was low due to the stickiness among particles. While the vacuum-dried sample had a low wettability time due to larger particle size, it was much longer in the spray-dried sample. Furthermore, the vacuum-dried sample had a lower hygroscopicity value (30.04%) than the spray-dried sample (37.26%), and chestnut bee pollen (32.58%). However, the spray-dried sample particles had a more homogeneous microstructure. The results highlighted that honey powder can be obtained by adding bee pollen as a carrier material with both drying methods, but the physical properties of powders should be improved by changing the product formulation and/or optimizing the drying conditions.